Kingdom Hearts: Three Houses
by pkpulakkmr
Summary: Just a little crossover story where Fodlan gets consumed by the darkness soon after the Flame Emperor's insurrection, causing the battle of the next five years to shift to the quest for Kingdom Hearts. I'm starting from the events of Hollow Bastion.


"Dedue!" Dimitri ran over to him right as he buckled over in pain. "Dedue, are you alright?!"

"Huh. So you finally came." A woman's voice rang out, and Dimitri looked up.

"Edelgard." he balled his fists. "So this is what you're stooping to? Killing anyone who gets in your way?!"

"He was the one who tried to kill me," she said. "He's under the mistaken impression that he needs to rescue our teacher from me when I do not mean them any harm."

"You're deluded," Dedue grumbled. "You're deluded if you think your so-called allies will help you!"

Dimitri drew his Keyblade and stepped in front. Lysithea stepped forward too.

"I'm done trying to negotiate. Take us to Byleth now, and renounce your alliance with those who slither in the dark. If you don't, you're no better than the Heartless!"

Edelgard simply smirked in response.

"We've always been rivals, haven't we? Pushing each other, trying to forge our own destinies. I never really stopped thinking of what role you'd play in my journey, Dimitri. And I've been wondering. That Keyblade, you got it right after we were separated during the Heartless invasion, correct?"

"Uh...right." his gaze faltered as he said that.

"So, if my understanding is correct." Edelgard raised her arm, and seconds later, Dimitri lost his grip on the Keyblade. "Ah yes, Arundel was right. I was the one intended for this destiny after all."

"W...what?!" Dimitri gasped, dumbfounded.

"The Keyblade chose me, not you. I just needed you to deliver it. Your role ends here, Dimitri. You can't save our teacher and unite Fodlan. That destiny is mine alone."

"Hold on, wait a minute!"

"Here." she threw something over and he caught it. It was a wooden sword, the one they used for training matches back at Garreg Mach. "If you insist on playing hero, go ahead and use that."

Lysithea's demeanor had shaken.

"Ah yes, Lysithea. Claude did tell the Alliance to follow the Keyblade's chosen, didn't he?"

"Uh...yeah, he did."

"Then I suppose a change in your allegiance is in order, yes?"

"Y...yes." she slowly made her way to Edelgard.

"Dammit..."

"Sorry, my captain told me to follow the Key, no matter what. I need to do this."

And just like that, they both walked away, leaving Dimitri behind.

"I won't stop," Dedue said, getting up. "I don't need a weapon to deal with the Heartless. I...I used a Crest stone, Dimitri. It was an act of desperation. You...you could say I turned myself into a beast."

"Beast or no beast, I'm just glad you're okay, Dedue. After the darkness was unleashed, I thought I'd never see you again." he then got up, the resolve firm in his eyes. "I'm not giving up either. Edelgard says that she'll be the one to save Fodlan. To save our teacher. But if that means going along with the plans of those who slither in the dark, I won't abide it! I will stop her, and make her see the error of her ways!"

"Happy to hear it, master. Now get behind me, the Heartless are coming!"

With Dedue's aid, surviving the hollow bastions proved easier than Dimitri had feared. As they resolutely cut through the heartless, they continued to search for Byleth, and for those who slithered in the dark, determined to put a stop to the machinations in place before it was too late.

* * *

Arundel looked at his stopwatch and smiled.

Yes, it was almost time. Soon, the Seven Princesses would unlock the path to Kingdom Hearts, and he'd be able to use the darkness of the abyss to shape the world as he saw fit.

Fodlan had been consumed for five years by now. Five years during which the Heartless would have eroded everything except the shell of what the land used to be. And once those who slithered in the dark had absolute command of the darkness, they would erase every trace of the Goddes Sothis's creation, and become as Gods themselves!

He looked aside and saw Edelgard looking over the coffin where Byleth was resting. Yes, this unwitting vessel for Sothis, the key to the final heart itself, had proven to be an invaluable tool-

A tremor. Could it be...?

"It seems the intruders didn't heed my advice after all," Edelgard said, her expression darkening.

"Then I suppose you know what to do."

"I do." she clutched her blade. "This time, they'll die."

* * *

"In here!" Dedue said, as they finally broke into the castle's chapel.

And Edelgard was waiting for them, with Lysithea in tow.

"Out of our way!" Dimitri said as Dedue stepped forward.

"Your obsession is appalling." she said, "If you had any sense in you, you would've turned back already."

"I'm taking Byleth back with me, and I'm not letting those who slither in the dark decide our future!"

"And you think I am?" Edelgard sneered. "I don't care for those fools other than as a means to an end. They will revive our teacher, give back their heart."

She drew her Keyblade. "And then, the two of us will open the door together! We'll use Kingdom Hearts to rebuild Fodlan, side by side! And as for Arundel and those vile cultists, they'll be crushed beneath our might! With my Keyblade and my teacher, I know I won't lose!"

"What...?" Dimitri muttered.

"So in the end, you simply believe that you need to be the one to make our world whole again." Dedue stepped forward. "An admirable disposition, if you weren't so hopelessly naive."

"Naive...? I'm doing everything I can to save us all! I'm the one taking action, making the hard choices!"

"And your choices are wrong, Edelgard," Dimitri said. "I can't abide by what you're doing. So I'm going to give you one last warning. Stand aside."

"You? Warn me?" Edelgard's expression morphed into one of undisguised contempt. "You're the defenseless one! Let's see if you survive THIS!"

She unleashed a dark beam that made a beeline straight for Dimitri, but it was promptly deflected...

...by none other than Lysithea herself.

"Dedue, you flank her left. I'll take her right. We'll need to keep Dimitri covered as we take her!"

"WHAT?!" Edelgard's composure had faltered. "No, don't do this!"

"I don't need a weapon, Edelgard. I have my friends. I have a heart that believes in a better way!" Dimitri said as he raised his arm. "I don't need anything else to best you!"

And in that instant, the Keyblade left Edelgard's grip and went over to his.

She bowed her head, her expression hardening into one of resolute bloodlust.

"Very well. If this is the way my journey's destined to be, I won't hold anything back!"

She then came upon them, her own ax ready and eager for the kill.

But as fierce and as determined as she was, she couldn't break through. Not when three foes of such great caliber were opposing her. But she continued to press forward, continued to attack...

Until a sharp pain in her arm forced her to let go of her ax, sending it flying across the room.

"Gh!" she grunted, as she saw her pursuers close in on her.

And so she turned around and ran.

"After her!" Dimitri yelled, but the passageway straight ahead was quickly sealed off by Edelgard's dark magic.

"Well, it seems as though we'll need to find another way," Lysithea said. "How about we take a look around."

"Lysithea, I just wanted to thank you," Dimitri said. "Defying your lord's order, it couldn't have been easy."

"It's no problem. I'm sure he'll understand." she said, with a carefree smile.

* * *

"Dammit!" Edelgard cursed as she wandered the dark halls. She'd made up her mind. She'd chosen to stain her hands and her heart.

And yet, she was the one who'd been forced to retreat.

"It...it was mine!" she muttered.

The Keyblade. Her destiny. She knew. She knew she had to be the one to open the door to Kingdom Hearts. It was the only way she could justify her existence. After all, she was the one who'd survived the horrors. The horrors of those who'd tried to forcibly implant the magic of light in her and her family.

And she was the only one who'd survived that. There had to be a reason why.

And if the power of darkness was what it took to unleash a new future where no one would have to suffer as she did, where she and Byleth could start a new life, safe in the knowledge of the world they'd saved, she wouldn't hesitate to embrace it!

"You have been defeated, but not destroyed, Flame Emperor." a voice called out to her.

"Huh, who's there?" she looked around but saw no one.

"For an instant, your heart faltered. For an instant, your resolve was weak. But you will find a path to victory. You always do."

"Who...who are you? Is it you, Hubert? Are you here?"

"No. I'm just another seeker. Same as you. But soon, you will see Hubert again. As well as Petra, Bernadetta, Lindheardt, and all of your other Black Eagles. Because you will never stop. You will never give up."

"Yes, I won't! I won't give up! So tell me! Tell me how I should fight back! Tell me how to stop my enemies!"

"Search your feelings, Edelgard. You already know the answer. When darkness ravaged Fodlan, you embraced it, knowing it could bring about the change you so desired! Where others cowered, you rose! Where others saw calamity, you saw an opportunity! Embrace the darkness that is calling out to you! Let go of all your inhibitions, and your strength will be insurmountable!"

"Yes, I'll do it! I'll give myself over to the darkness if that's what it takes!"

**_"I will become darkness itself!"_**

* * *

"You brats! I see you'll insist on interfering till the bitter end!" Arundel said as the three pursuers entered the Grand Hall.

"Of course we will!" Dimitri said as he drew his Keyblade. "You've ravaged countless worlds just to abduct innocent people you wish to use as tools! You even corrupted Edelgard! I'll never forgive you!"

"Once we've dealt with you, you're going to tell us where those who slither in the dark are. We'll put a stop to every last one of them!" Lysithea bellowed.

"Oh, now that's an interesting statement," Arundel said with a vicious smile. And just then, he began to transform into a silver-haired warrior in black armor.

"Tell you where those who slither in the dark are, huh? Why I'm the man who leads them! Prepare to be ravaged you poor fools, because you've crossed the one and only Thales!"

"It was you! You were their dark lord all along!" Dedue screamed in rage.

"Indeed, and I'll crush you beneath my power!" he bellowed, as swarms of Heartless began to gather around him.

"This is going to take everything we have!" Dimitri said.

And sure enough, it did. Dedue and Lysithea underwent tremendous strain in using their powers to protect Dimitri and match Thales's relentless assaults. Dimitri busied himself with holding off the veritable army of Heartless that were swarming them.

But in his arrogance, Thales had not accounted for his enemies adapting to his attacks. Soon, his defenses were getting penetrated, more and more. What started out as a few pitiful attacks he easily deflected became a series of well-crafted assaults he had to work hard to evade. And the more he focused on defending himself, the less he could focus on overwhelming his enemies.

Which was why, in the end, it was Thales who crumbled under the overwhelming might of Dimitri, Dedue and Lysithea, and desperately conjured up a portal to escape a decisive defeat.

But even that effort was doomed to failure, as his pursuers immediately followed after him before he could seal the path behind him.

Cornered, he looked for anything, anyone that could save him, and to his surprise, he found her.

"El..." Dimitri blurted out, as he saw Edelgard standing in what looked to be an antechamber. She looked at him with a gaze that seemed more amused than anything else.

"It seems the enemies have overwhelmed you, Thales. Need any assistance?"

Begrudgingly, he looked to her and nodded.

"E...Edelgard, what are you doing?!"

Dimitri froze as he saw her draw a Keyblade.

"Where did you get that?"

"This? This is nothing but a tool. A tool I can use to unlock the potential within people's hearts." Edelgard said, as though she'd been using that Keyblade all her life. "Thales, I'm going to make sure you hold nothing back. You've always relied on the darkness, a servant to it. And for that, you should be proud!"

She readied the Keyblade. "Now, open your heart! Embrace the darkness! Become darkness itself, and eradicate all who oppose you!"

And then she stabbed him through the heart. And Thales transformed once more.

"Yes! YES! This is it! This is true darkness! THIS IS THE POWER I'VE ALWAYS LONGED FOR!"

"DEFEND YOURSELVES!" Dimitri yelled, horrified of what he was witnessing. Thales had transformed into a grotesque demon, with a black taint covering his face, red dots where his eyes should've been. And black, slimy wings that sprouted from his shoulders.

The battle was absolute madness, as they desperately fought back against the berserk demon. It didn't seem to hold even a sliver of intelligence as it mindlessly sought to destroy everyone in the room.

Dimitri was also shaken by the savage bloodlust awakening within him, the darkness in his own heart that he'd been acutely aware of for so long.

But he had no choice. He had to give it everything he had to vanquish the monster before him, to ensure that he could survive and save those he cared about!

"AAAARGH!" he didn't even notice that the demon had ceased moving until it disintegrated into ash while he was still stabbing it. As the truth slowly dawned on him, he staggered back, terrified of what he'd become.

"His was a mind consumed by arrogance," Edelgard said. "He felt entitled to a kingdom he never owned, adulation he'd never earned. Small wonder he'd seize upon any opportunity to cow others into submission. A perfect tool to be used and thrown away."

"You..." Dimitri muttered in rage as he looked up to her. "How dare you..."

In response, Edelgard simply conjured up a portal and headed back to the Grand Hall.

"GET BACK HERE!" he screamed as he jumped through. His allies, Dedue and Lysithea did as well, but a force-field repelled them, bringing Dimitri to his senses.

"Hey! Are you two alright!" he said, looking for them.

"Yeah! But we can't get to you!" Dedue said.

Dimitri then turned to face Edelgard.

"Edel...no, you can't be her! You're not Edelgard!" he said, drawing his Keyblade.

"Indeed, I'm not. It was clear that she lacked the power to defeat you, so I simply took her out of the picture." the woman said, looking completely unfazed.

"What? Where is she? What have you done to her?!"

"Why should you be so worried?" the woman said, her smile turning vicious. "After all, she was the Flame Emperor. The one who repeatedly sought to have you killed. The one who ruined the peaceful years you'd spent as a student. The one who embraced the darkness as it engulfed Fodlan. Didn't your heart scream for her blood when you discovered her true colors? Didn't it recoil in disgust when you discovered she had no remorse?!"

"Shut up," Dimitri said, hardening his grip. "Don't you dare talk about her that way!"

"Why? You know I'm not lying. Every word I spoke is true."

"Even so, you don't get to tell me I shouldn't care! You don't get to take her away from me!"

"She will spend an eternity in darkness, repenting for her actions, ashamed of her powerlessness! Is there not a more fitting end for someone such as her?!"

"I SAID SHUT UP!" Dimitri swung his Keyblade. It was easily deflected, but his resolve didn't waver. "Regardless of our past, of what she's done, I still consider her a friend! I forgive her, I understand her, and I care about her, and I know that deep down, she cared about me too! I won't let someone like you tell me she's not worth saving! I'm going to bring her back with me, no matter what!"

"People like you are so strange indeed. Truly beyond comprehension." the woman then snapped her fingers, and what happened next made Dimitri's eyes widen in shock.

"Byleth!"

"Indeed, your teacher lies right there. The one you've all been trying to save."

The woman snapped her fingers again.

"Kh!" Dimitri grunted as he felt a rumbling in his chest. "What...what's happening?!"

"You've carried Byleth's heart all along Dimitri. I needed you to come here. I needed you to awaken them."

"What...?"

"Within your teacher lies another heart. The one of the final Princess, Sothis. But to awaken her, I need to awaken them. And to awaken them, I need to awaken you."

"Me...?"

"Yes." she drew her Keyblade. "You will give me your heart, and release the heart of Sothis's vessel! And then, I will seize Sothis and unlock the final Keyhole!"

"Who...who are you?!"

"Nemesis, the Seeker of Darkness." she said, as she brought her Keyblade down to strike.

_"Dimitri!"_ Byleth's voice rang out.

And in that instance, he intercepted the strike.

"Forget it," he said. "There's no way I'm letting you lay a finger on Byleth. You're going to give me back what you took! All of it!"

Nemesis giggled contemptuously as she saw the resolve in Dimitri's eyes. "So, not going to give up without a fight? Very well, HAVE AT YOU!"

And so their duel began, with Dimitri more determined than ever to emerge victorious. He knew that he had a lot to lose, but he had faith. Faith that he would come through for all those he loved and cared about.

And if saving Edelgard's heart meant rending her body, it was a price he'd happily pay!

However, having to fight alone without his friends backing him up made the battle one of the most strenuous he'd ever fought. Especially since he was still shaken up by the bloodlust that had awakened within him just a few moments ago.

But nonetheless, he persevered, focused on weakening the Edelgard vessel as much as he could. A vessel that had been pushed far beyond its ordinary capabilities thanks to Nemesis's possession.

"Come, open your heart Dimitri! Give in to the power of darkness!"

"Shut up!"

He wouldn't let Nemesis get to him. Not when there was so much at stake!

His home. The Blue Lions. Claude. Edelgard. Byleth.

He would stop at _nothing _for them!

"AAARGH!" with one final slash, he incapacitated the Edelgard vessel. And just as quickly, it vanished from sight.

"Wait, no no! Edelgard! EDELGARD!"

"Dimitri, are you okay?" Lysithea said as she ran up to him, Dedue in tow.

"Y...yeah. It's just, Edelgard's..."

"We know. We saw everything." Dedue said. "We'll find her, Dimitri. Together."

"Yeah, I know we will." Dimitri said as he looked around.

"So is that the final Keyhole?" Dedue pointed at the large rainbow-colored portal in front of them.

"Yes, I imagine it must be." Dimitri said as he pointed his Keyblade.

"It's...not working." Lysithea said.

"It's not completed. Sothis's heart is still sealed." Dimitri said as he sheathed his Keyblade.

"So what do we do?" Dedue said, and just then Dimitri picked up the dark Keyblade Nemesis had dropped.

"Wait, don't tell me you're-"

"This is different from the other times," Dimitri said with a smile. "I know I'm not throwing my life away."

"Wait, DON'T!"

But it was too late. Without another moment's hesitation, Dimitri plunged the Keyblade into his heart. And so, the sealed hearts were unleashed, flowing into the Keyhole and completing it, while Dimitri vanished.

* * *

"I leave it all to you now, teacher," he spoke into the void as he fell.

"With you to unite us, I know we'll all be together again eventually."

* * *

"Gh!" Byleth said, waking up.

_"The Keyhole, it's complete."_

"Teacher! Teacher, are you alright?!" Lysithea said as she rushed towards them.

"Yeah, I'm okay. Is this the final Keyhole?"

"Yeah. And Dimitri, he's gone. When he awakened you, he..."

"Hehehehe!" a malevolent voice rang out.

"What?" Byleth said as they got up.

It was him. Nemesis, in his true form.

"Now the path to the door is clear. You did well to bring Sothis here, mercenary." his smile was dripping with condescension. "But now your part is at an end. Soon, I will reveal the secret of Kingdom Hearts and unleash everlasting darkness unto the worlds! And I'm afraid I can't have you in my way."

"Don't make another move!" Dedue said, readying himself. As did Lysithea.

"Wait, are you sure you can take him on by yourselves?!" Byleth yelled.

"We have to try!" Lysithea said as she readied her magic.

"Heh, stubborn till the very end I see. It doesn't matter, I...kh!"

Nemesis winced as he felt something bear down on him. It was heavy and sharp...like an ax!

"I...won't let you use me anymore!" Edelgard screamed as she blocked his path. She wasn't physically present, not quite, but everyone could sense her heart. Her heart that was doing all it could to keep Byleth and his companions safe.

"Run, teacher!" she yelled. "The heartless are coming! They'll swarm this place!"

"Edelgard..." Byleth muttered as they reached out, but Dedue pulled them back.

"Come on, we've gotta go!"

"I guess sealing the Keyhole will have to wait!" Lysithea said. "Make for the entrance, you two! I'll cover you!"

And so they made their escape. But a Heartless had slipped through their defenses. A Heartless more determined than the rest.

* * *

Byleth reached the entrance hall and made a beeline for the Gummi ship, but was stopped in their tracks.

The lone Heartless just stood there. Not approaching. Not attacking.

"Is that...?"

_"Yes, he is! We have to protect him!"_

Dedue followed but froze when he saw Byleth lift up the Heartless.

"Byleth, what are you doing?!"

"It's Dimitri! We're taking him!" Byleth said, just as Lysithea came in...with a horde of Heartless chasing her.

"Cover me!" Byleth yelled, and Dedue nodded and rushed over to her.

"This time, I'm protecting you, you hear me Dimitri? You're coming with us, back to Fodlan, back to Garreg Mach, you hear me?!"

The invading Heartless had sealed the way out, forcing the four of them into a corner.

"I...I'll go all the way if I have to!" Dedue yelled. "We need to protect Dimitri and our teacher at all costs!"

"Wait, did you say Dimitri?" Lysithea turned to him in shock.

And just then, a Keyblade materialized and swept the Heartless away. It was wielded by none other than Dimitri himself.

"Wha..."

"Master...?!"

"Huh, to think it'd be so soon," Dimitri said, apparently just realizing that he'd returned from the void. He then turned to Byleth.

"You never cease to amaze me. I'd hoped that you'd bring me back, but to think it'd be so soon, I..."

He was cut off by a fierce hug.

"Welcome back, Dimitri. And thank you, for keeping me safe all this time."

"And thank you, for bringing me back teacher. Not just this time, but all the times I've faced the brink, when I nearly gave in to the darkness."

"I know. It's only by the power of our bonds that we're able to keep from getting lost in the abyss. And we have so many more to save from the darkness, don't we?"

"Yes, we do." Dimitri said, resolutely.

* * *

Edelgard lay down despondent, once again banished to the void.

Through sheer force of will, she'd resurfaced to protect her teacher. To put a stop to Nemesis, if only for a short while.

But now it was over. She would spend the rest of eternity lost in the darkness, never to find a way out.

How ironic, considering that her ambitions had been driven by the knowledge that she'd likely see her end before the rest of her peers. That she needed to act swiftly and decisively to create the Fodlan she wanted to live in. But perhaps her very eagerness had spelled her doom.

Now, regardless of who won or lost, Edelgard would not be around to see the outcome. She had, now and forever, lost control.

It was a despairing realization, of course, but in some ways even a comforting one. She no longer felt she had to fight anyone else's vision or push someone out of the way to protect her own ideals.

The worst outcome that she had feared had already happened, and so she couldn't do anything more than accept her fate, and pray that the comrades she'd left behind faced a better one than she had.

_"...Edelgard! Lady Edelgard!"_

"Huh?" she perked up and looked around. "Who's there?"

_"Huh? Can you hear me? Lady Edelgard, can you hear me?!"_

"Yes, I hear you! Who is it?"

"Oh, finally! I've finally found you!"

His voice rang clear now. She couldn't believe it.

But sure enough, he soon arrived before her, and she had no further room for doubt.

"Hubert!" she screamed and ran into his arms. "Hubert, it really is you!"

"I...I found you at last, El..." he murmured. "It...wasn't easy, fumbling my way through the dark."

"You...did you come here, all this way, for me?"

"Of course I did. You know I'd follow you anywhere."

"Hubert, you...really didn't have to." she tried to keep composed but could stop the tears from flowing.

"It's my duty to ensure you're never alone in your journey, Lady Edelgard. It's one I chose of my own free will. Thus, I did have to follow you, to assuage my own conscience."

"I...I'm all alone here now, Hubert. I left them all behind, and I'll never see them again. And I know I'm simply facing the consequences of my actions, but it still hurts!"

"That's not true. There's still a way, Lady Edelgard. I found the door."

"Wh...what?" she looked up.

"I can take you to Kingdom Hearts. There's someone there who'd like to see you. He has the third Keyblade."

"Could it be...is it _him_?"

"Your intuition is on point. He's looking for you. He says he needs your help in sealing it, but we could kill him and use the door to bring about our new world if you wish! Whatever your choice, I'll gladly see it to the end!"

"No." Edelgard balled her fists. "This time, I'm not going to shut out my friends. I'll finish my journey by their side, no matter what!"

"Oh..." Hubert look surprised for a moment, before a barely-perceptible relief crossed his expression, as he bowed. "As you wish, Lady Edelgard."

* * *

_If you are reading this, it means I've been lost to the darkness._

_Though I swore to serve Lady Edelgard with my every breath, once the Heartless came, I never saw her again. I knew not where she was, what she had planned, or if she was even alive. I had no choice but to follow my own heart, to make my own calculations for what was best for her future, to have faith that she would emerge victorious no matter what._

_Then I learned of what had happened in the hollow bastions. Perhaps you are surprised that I did not pursue you to seek vengeance, knowing that your interference caused her to disappear. But my heart told me there was a better way. My heart told me she wouldn't have wanted me to ravage you on her behalf._

_And so I share with you now the final world opened by those who slither in the dark. It is a haven for the Heartless, and the graveyard of Fodlan. Though you have vanquished their leader, the darkness there grows stronger still. That means a greater evil has been unleashed. It is an evil I do not understand, but perhaps you may have already faced it._

_I leave it to you to conquer the darkness from the abyss known as Shambhala. The final Keyhole in the hollow bastions has already been sealed by the wielder of the third Keyblade. I will find him and Lady Edelgard, and once I do, his final fate will rest on her choice._

_But somehow, my heart tells me we'll all see each other again soon. Perhaps my days of staining my hands for her sake may truly be at an end. __If so, that truly would be a bittersweet moment indeed._

_I have enclosed the Gummi Nav that should open the path to Shambhala. May your heart be your guiding key, Dimitri._

_Your humble messenger,_

_Hubert_

* * *

Dimitri folded the letter as Dedue looked on ahead.

"I can see it! It's another world, alright!"

"It must be Shambhala! Find a landing spot, we must disembark!" Dimitri said.

And so, the three of them finally made their way into the final world.

Their teacher had wanted to come too. Byleth had wanted to help.

But they needed them to stay behind. Once Nemesis was defeated, and Kingdom Hearts sealed, the worlds lost to the darkness would become whole again. However, the world borders would return as well, and thus no one knew if anyone would remember what transpired, or if it would even be possible to explore different worlds anymore.

And so, they needed Byleth to be safe, so that their teacher could return to Fodlan and help it rebuild in case no one else made it back. They needed to ensure their home would still have a future, even if they couldn't be around to see it.

And so Byleth relented, promising to return to Fodlan once it was whole again, no matter what.

Dimitri looked upon the vast expanse before him. There were so many worlds here, fragmented, scattered. Who else had lost their homes to the darkness? Who else was leaning on them to make their realms whole again?

"Almyria..." Lysithea said as she clenched her fists.

"Yes, come to think of it, we have no clue what became of them, do we?" Dimitri said.

"Of course we don't. Claude...you have no idea how deeply he wanted to unite the two lands. But with all this darkness, that dream seems further away than ever."

"We'll restore the light, Lysithea. I promise you. And then you can fight for that dream in his stead until he comes back to you." Dimitri said.

They steeled themselves and marched forward.

It was a strange experience, having no one but each other to rely on as they battled their way through shifting landscapes, Heartless who were more powerful than ever, a world that seemed determined to trap them in an endless, incomprehensible maze.

But their hearts were also stronger than ever, and so they moved resolutely on ahead, even as their eyes couldn't tell where one path ended and another began. They knew that with every step they were inching closer to their destination.

The door to Kingdom Hearts was here. And Nemesis was waiting for them.

* * *

"On your six!" Dedue yelled, as Dimitri turned around and struck the Heartless who has sneaked up on him.

Lysithea was nearing her limit, making the most of the powers her Crests had given her.

Dedue had been channeling his beastly nature for a while now, keeping Dimitri safe as he struck down Heartless after Heartless.

"Don't give in!" he yelled as he slashed another foe away. "We're not done yet!"

"Understood! I'll...hold on! For the sake of our friends, I'll hold on!" Lysithea screamed as she unleashed another spell.

"We'll make it out of this! All of us!" Dedue yelled.

And so they continued their dance with the Heartless horde, unwavering and determined to survive till the end. Just one more foe. One last wave.

The final path would open any moment now.

"AAARGH!"

"HYAAAH!"

"EEEEEEH!"

They pushed and pushed and pushed. Until suddenly, the last Heartless was vanquished, and the path ahead of them opened, welcoming them to step through.

And step through they did.

* * *

"Wha...?"

Dimitri looked around. This couldn't be right. Why was he here?

His father lay dead before him. His mother was nowhere to be seen. And...was that him, clinging to Glenn's body?

"No, no you wouldn't do this, don't do this to me! Wake up, please wake up!"

Glenn had died...so that Dimitri might live.

_"It was the Duscurs! Those savages murdered our King!"_

_"Exterminate! Annihilate!"_

_"No! No, you're wrong! Why won't anyone listen?! Please, I beg of you!"_

_"Avenge them, in the name of our Mother!"_

More flames. Destruction. Death.

The darkness in their hearts made manifest.

And in those flames, stood the Flame Emperor.

"...was it you?" Dimitri muttered. "Did you do this?"

The Emperor turned around and left, without a word.

"Come back! I said GET BACK HERE!"

Losing his reason, Dimitri chased after that figure.

"ANSWER ME! DON'T YOU WALK AWAY!"

Just as Dimitri pounced on the enemy, the world shifted again. Now, he was in a dark place. A damp place. A dungeon.

"Father...please...someone...he...lp..."

The voice. It sounded so familiar.

His eyes widened in horror. "No..."

"GYAAAAH!"

"This will only hurt a little. What comes next, more so."

"KYAAAAAHHHH!"

"No...please...don't hurt her! Don't...hurt my sister. Ple...ase..."

11 children. Cut open, and sewed back. All screaming. All hurting.

Withering away. Sacrifices made in the name of light. In the name of power.

"Help us...somebody..."

"El...is this..."

_"I will take that head from your shoulders, AND HANG IT FROM THE GATES OF ENBARR!"_

"NO!" he yelled. "No! I'm sorry, El! I didn't know, I didn't know! I'm so sorry!"

Those hungry for power. Using the darkest of methods, to unleash the light.

"No...no..." he was sobbing now.

Why? Why did they all suffer this way? Why could they never understand each other? Maybe if he'd been better...if he hadn't given in to his own darkness.

"Dimitri! Wake up!"

"AAARGH!" he screamed and quickly regained his bearings when he realized Dedue was the one calling out to him.

"You...you look like you've just seen something horrible," Lysithea said. "Are you okay?"

He reached out and touched her hair. "Your hair, it's...oh God..."

Her gaze grew somber, as though she'd just understood what he'd seen.

"Where are we?" Dedue yelled. "Who's doing this?!"

As if in response to his words, the scenery changed once more. They were in the midst of a battlefield. Corpses surrounded them as if lining a path. A path that led to...

"El!" Without hesitating, Dimitri got up and ran over to her. Dedue and Lysithea followed.

"This world seems so small to those stripped of their agency." Edelgard began, but Dimitri immediately realized it wasn't really her.

She turned around, adorned in the garb of a queen, and a warrior. A crown with horns. A red gown that may very well have been bathed in the blood of the dead who surrounded them.

"For this girl, who's entire will was forged in the turmoil of injustice, this realm was nothing more than a cruel prison. Deserving only of annihilation, so she could rebuild it with her own hands. And so, to free herself, she opened her heart to darkness!"

"El, please!" Dimitri reached out, but she was gone. Only Nemesis stood in her place.

"Don't bother. Your voice can't reach her where she is. I told you didn't I? Her heart now eternally belongs to the darkness!"

"Damn you..."

"All worlds begin in darkness, and that is where they also end. The heart is no different. Darkness sprouts within it, and then it grows and consumes it!"

Nemesis vanished from their sight, only to appear behind them.

"In the end, every heart must return to the darkness from whence it came! You see, darkness is the heart's true essence!"

"You're wrong!" Dimitri yelled. "Yes, the heart is fragile. And yes, it can even give in. But deep down, there's a light that never goes out! Because we don't let it! We persevere, overcome and look past what divides us! Even if my shadow never leaves me, I will never let it take over!"

Nemesis simply looked at him with contempt and dismissal.

"So, you have come this far, and still you understand nothing. Every light must fade! Every heart, return to darkness!"

He then rushed forward, his blade drawn to cut down Dimitri where he stood.

But Dimitri wouldn't lose so easily.

"Very well then. COME FACE ME, NEMESIS!" he yelled as he swung his Keyblade, blocking the attack.

"AAARGH!" Nemesis swung again, catching Dimitri in a deadlock. But Nemesis was soon forced to retreat when Dedue and Lysithea caught up to him.

"Hmph, you think your friends can save you? All you're doing is prolonging the inevitable!"

"No, we're taking back what's ours!" Lysithea yelled as she unleashed an attack that staggered him. Dimitri then closed in.

"Gh!" Nemesis barely blocked the attack.

"Having a little trouble there? Where's that darkness of yours now?!"

"Insolent little...SUBMIT!"

Dimitri felt a sharp pain as he sensed something malevolent enter him.

"Master are you alright...?" Dedue yelled as he rushed to him, but Dimitri warned him to stay away.

"Focus...on...the enemy..."

"Hehehe! Let's see how long you last against my gift!" Nemesis said, even as Dedue and Lysithea continued to pursue him. "Come, open your heart!"

Dimitri collapsed, clutching his chest as he felt the monster squirm inside him. But he wouldn't give in. He would never give in!

"I won't let the darkness take me!" he yelled, as he pushed through the pain, pushed back against the invader violating him.

And then, Nemesis lost control, and Dimitri could breathe again.

The chance to strike had never been clearer.

"AAAARGH!" with one powerful swing, his Keyblade struck true, cutting through Nemesis's defenses and bringing him to his knees.

But just as Dimitri readied his Keyblade for the final blow, a forcefield separated him from Dedue and Lysithea.

"Now then," Nemesis gave a bloodthirsty grin as he got up. "It's time I relieved you of your delusions and delivered you to the darkness for good!"

Dimitri barely evaded the next attack, a charging blitz that took the wind out of his sails.

And that was only the beginning.

Nemesis was faster. More ferocious. His tactics sought to overwhelm him. He could barely keep up.

His vision was dimming. His senses were dulling. Soon to be overtaken by darkness.

Darkness...

No...he wouldn't...not when he still had his friends to fight for!

Nemesis was just a blur now. A blur closing in for the kill.

But a moment was all Dimitri needed to sharpen his senses and shine a light on the deception of his enemy. To shine a light that would cut through the darkness.

"HYAAAH!" Dimitri ran through Nemesis right as he got within range. There was no doubt left on who was the victor.

"Dimitri!" Lysithea said as she ran over to him. Dedue was not far behind.

But just as he smiled in relief at seeing his fellow comrades again, his jubilation was cut short by a cruel laugh.

"Heheheh, hahahahaha! Fools, every last one of you!"

"Nemesis..." Dimitri clutched his Keyblade. No, how could he still be...?

"Behold, the door that lies in this endless abyss! Kingdom Hearts!"

They noticed now. How all their surroundings had just melted away. How there was naught but an endless void to be seen.

And a door...was that truly _the _door?

"Look as hard as you're able! You will not find a single speck of light! From the depths of that darkness are all hearts born! Even yours!"

Dimitri was the first one to realize.

This was Nemesis's final form.

A being cut from the blackness of the abyss itself. A grotesque, chimeric shadow, at whose core stood the man. His eyes hollow. His hunger radiating stronger than ever.

Nemesis would stop at nothing to serve the darkness which surrounded him.

"Darkness CONQUERS ALL WORLDS!" He yelled, and Dedue and Lysithea were immediately swallowed by the shadow.

"No! No, where are you! No..." Dimitri could feel that shadow creeping up to him, mercilessly swallowing him whole.

_"no..."_

* * *

"Don't give up, Dimitri! Not now!"

_El...?_

"Come on! I know you're stronger than this!"

_The light...could it be...?_

He'd gifted it to her all those years ago, hadn't he? That dagger?

Right as she was about to leave, he'd hastily given it to her. It was pure instinct. He couldn't think of anything else to give.

Years down the line, he'd often wondered if it was a silly thing to give her. Certainly something unfit for a lady.

But he knew, deep down he knew, that the dagger represented his dearest wish. His wish that one day, that sweet girl he knew would cut a path to her own future.

"It's your turn now, Dimitri! Cut a path to the light, for me! For all of us!"

"Yes. I'll do it...for you!" Dimitri screamed, as the dagger transformed into the Keyblade. Immediately, the shadows were repelled, and his sight was clear.

Nemesis was there, at the center of the monstrous shadow. Dimitri did not hesitate as he flew straight to him.

"Defiance is futile!" Nemesis bellowed as he intercepted Dimitri's strike. "Here, the darkness is endless! Eternal!"

But every swing of Dimtri's Keyblade proved him wrong. His shadow was being illuminated, its weaknesses exposed, its terror diminished.

And Dimitri could feel it too. All those prisoners of the abyss, begging for release, so they could exact retribution on the darkness that had blinded them for so long.

"I'll ensure you suffer for your insolence! RETURN TO DARKNESS!" Nemesis screamed as Dimitri found himself swallowed by another shadow.

But this time, he wasn't lost. His heart was lighting the way.

A crowd of fighters, fending off the Heartless. He could see them. And he was going to save them.

"AAARGH!" he cut through every Heartless in his path.

"Master!" Dedue yelled as he ran towards him. "They're here! The Blue Lions!"

"Dimitri! Is that really you?! So Dedue was right, you really were fighting for us!" Sylvain sighed in relief.

"Come now, did you ever really doubt me?" Dimitri said as a red, pulsating Heartless approached them.

Together, at last, the Blue Lions combined their strength and took it down in one fell swoop.

And then they were freed. Freed to look upon Nemesis's chimera.

"So that's what kept us imprisoned," Mercedes muttered. "That's Nemesis!"

"He is," Dimitri said. "We need to cut down this shadow and eliminate him for good!"

The Blue Lions did not hesitate as the swarmed Nemesis, but Dimitri couldn't help but notice something was off.

He'd found Dedue, but not Lysithea. She was still being held prisoner!

He carefully looked around and discovered a portal that seemed to lead into another dimension infested with the Heartless. Without hesitation, he crossed over.

He immediately readied his Keyblade and defended himself against the Heartless who swarmed him.

"Out of my way!"

"Dimitri! DIMITRI!" Lysithea yelled. "You're here! You came for me! For us!"

"So you were right! He really is here!" Hilda's voice rang out, "Let's vanquish the Heartless once and for all, everyone! For the Golden Deer!"

It seemed as though his arrival was all they needed to overcome their fears, as the Heartless began to dwindle in earnest.

"We're getting out of here!" Leonie yelled. "We're going to see our teacher again!"

"You're damn right you will!" Dimitri yelled, joining the fray.

It didn't take long for their enemies to be vanquished, with only one lone pulsating blue Heartless left to face them.

"This is just like old times, isn't it Marianne?" Hilda said.

"Yes, this time we'll win by the strength of our own hearts!" she yelled, and together they unleashed a vicious assault that obliterated the Heartless and freed them all.

"Claude would've been so proud to see that." Lysithea said as she returned to Dimitri's side. Just then, they were whisked back to Nemesis's shadow.

Dimitri gasped in shock as he saw the Black Eagles join the fight. Somehow, his own Blue Lions had found and freed them.

"They're all here, Your Highness!" Dedue said as he joined his side. "Nemesis is done for!"

"Do you think your pitiful band can overcome me?! I imprisoned you all before, and I can do so again! The might of darkness always claims victory!"

"You're wrong!" Ferdinand yelled. "Now that I have found my way out of the void, I will never let you drag me back there! Isn't that right, Black Eagle Strike Force?!"

"YES!" they all yelled.

"Prepare for your end, Nemesis! This is for Claude!" Hilda yelled.

"Everyone, thank you for this! Let's put an end to the darkness that tore us all apart! ATTACK!" Dimitri yelled, and they all rushed to vanquish their common enemy.

Nemesis did not stand a chance.

* * *

"AAARGH!" Dimtri held on to Dedue as they felt the entire dimension swirling and raging in chaos after Nemesis's destruction. It was all he could do to not lose his very senses to the turbulence.

He felt another hand grab onto him.

"Lysithea!"

"Hold on, Dimitri! You're coming back with us! We won't leave you behind!"

"Hehehehe! No, it's too late for all of you! I won't let any of you return!"

The three turned to face Nemesis, battered, but still alive.

"The worlds may be returning, and my hold over Shambhala may have weakened. But you forget, the key to reversing my fortunes is right there!"

He pointed to the doors, to Kingdom Hearts.

"NO!" Dedue yelled, but it was too late. Nemesis extended his hand, and the doors began to open.

"YES! Kingdom Hearts, fill me with the power of darkness, and erase the insolent fools that dared defy you!"

The doors opened wider and wider. There was no stopping it now.

"Yes, Supreme Darkness, consume all the worlds, consume all of us! Return us to our true natures!"

Dimitri, however, was completely unfazed.

"You're the one who's failed, Nemesis. You never understood, that our hearts cannot beat without the spark of light!"

And so, the light shone upon them all. The spark that kept the heart going, that separated the living from the dead.

That light horrified Nemesis like nothing else ever had.

"No, the light?! But why? WHYYYYY?!" he yelled as he vanished, his very being disintegrating into the light.

And so it was that Dimitri, Dedue, and Lysithea found themselves facing the door, their enemy finally vanquished.

"Come on, we need to close this!" Dimitri yelled as he pushed himself against the right door, while Dedue and Lysithea took the left.

"This...this is heavy...even my strength can't...Lysithea, what are you doing?!" Dedue yelled.

She was staring through the doors, into what lay beyond. Not able to contain their curiosities, Dimitri and Dedue did the same.

"The Heartless?!"

Swarms of them, more than they'd ever seen. If they ever crossed over through these doors, then everything they'd fought for, everything they'd done, would be for...

"Don't give up!" Dimitri heard a voice yell from the other side, and then, she leaned out to face him.

"El!" he couldn't believe it. She was here!

"Come on Dimitri, we can do this! Together!"

"Alright!" he pushed himself harder than ever.

"Come now, give it everything you have!" Hubert's voice rang from behind the left door. "We'll ensure no Heartless make it out to your side!"

"I don't know if we can do this...fast enough...!" Lysithea yelled.

Indeed, two lumbering Heartless were already marching towards the doors. There was no way any of them could hold them off!

Unless...

Two arrows of gold flew quick and true and vanquished the Heartless where they stood.

He was there, the gold in his armor shining through the light, his bow raised, ready to protect his comrades.

"Claude is that you?! CLAUDE!" Lysithea yelled in amazement.

"It's good to see you too," he said, with a carefree smile. "I was wondering when my aces in the hole would show up."

"Don't tell me," Dimitri couldn't help but chuckle, as he added jokingly, "Was this all part of your plan?"

"Hey, if it makes you feel any better, sure, why not?"

"But...but Claude, if we close the doors, then..."

"You don't need to worry about that, Lysithea." Claude's smile didn't waver, but his tone immediately grew sincere. "Remember what I said. There's always another door to the light. You believe me, don't you?"

The resolve in her eyes grew firm as Lysithea nodded. "Yes. I know we can trust you. Let's do this, everyone!"

"Hurry! Before more of them show up!" Edelgard said, and they all redoubled their efforts.

And soon, the doors began to close.

"Lysithea, when you're back with the others, tell them I said thanks, would you? And Dedue, make sure His Highness doesn't get wrapped up in _too much_ trouble." Claude said as he unfolded his bow.

It was the third Keyblade, and he was its wielder. And now, it was finally time to seal the path to Kingdom Hearts.

"Dimitri, ready your Keyblade once the doors shut. You've got this."

Dimitri nodded solemnly as he took one last look at the other side.

Edelgard was looking back at him, with a smile that was a mix of sadness, and hope.

"Look after our teacher, okay? Take care of them."

"I will." Dimitri said, doing his best to return a smile of his own. Whether she was convinced by it or not, though, he could not see, as the doors finally shut.

And so it was that the man in gold lifted his Keyblade and the man in blue his own.

And the woman in red, for the first time in her life, relinquished control.

* * *

_"Wrong foot, Dimitri, you're supposed to be leading with your right!"_

_"El, the sun's going down, I oughta head home..."_

_"...listen to me. No matter how hard things get, you can't give in, okay? You've got to cut a path to the future you wish for, no matter what."_

The memories were still with him, even though she was not. Edelgard had vanished, along with Claude and Hubert. Because the path to their side had been sealed.

What was he to do now? What future should he cut a path to?

Dimitri saw Byleth in the distance. Fodlan would soon be whole again. Hopefully the students they'd freed had found their way back.

He rushed over to where they stood.

"Teacher!"

He extended his hand, and Byleth grabbed it, just as the ground was beginning to rupture, the worlds separate.

"You...remember what you told me, all those years ago?"

Byleth nodded, "I said that no matter what, if you ever needed me, I'd find my way to you."

"Well, now it's my turn to make a promise. I'm going away for a while, but I'll be back. I'll find our friends, and return every last one of them!"

He felt another pair of hands hold his.

"We know you will."

"Lady Rhea...?"

"Get them back. All of them."

Dimitri nodded, and let go.

Lysithea and Dedue had never left his side, and so they too drifted away with him, as the fissures separated the worlds.

Byleth and Rhea looked on until the world border eclipsed the three, and they could be seen no longer.

* * *

_Fodlan saw a new dawn in an uncertain era. Most could not remember anything past the Flame Emperor's insurrection at Garreg Mach, and yet the Emperor was nowhere to be found, the monastery still in shambles._

_To the surprise of the Church, Lady Rhea called off the war effort that was being organized in retaliation for the rebellion against the Church, and anointed Byleth and the King of Faerghus, as they worked together to bring peace and stability to the lands._

_Hilda returned to lead the Leicester Alliance in the absence of Claude von Reigan. Maintaining the Alliance's stance on neutrality, she provided aid to the Kingdom and the Empire alike, despite incurring the ire of those who still wished retribution on the Adrestians for their perceived transgressions._

_Ferdinand von Aegir and Dorothea Arnault found themselves in the unenviable position of picking up the pieces and rebuilding the Adrestian Empire, facing violent insurrections from independently formed militias determined to avenge the assault on Garreg Mach. To everyone's surprise, Adrestia was soon receiving assistance from the Knights of Seiros, causing the embers of strife to die down over time. Nonetheless, the legacy left behind by the corrupt nobility and the machinations of those who slithered in the dark ensured that maintaining the Empire's strength remained an uphill battle._

_The whereabouts of the remaining students remain unknown, with several disappearing from public memory, their existence preserved only in the Church's records._

* * *

"Where do you think we are?" Lysithea said as they continued to walk down what seemed like an endless road.

"It's probably some sort of bridge. A world between worlds." Dimitri said.

"Do we even have an inkling of where we will find this other door to the light?" Dedue muttered.

"No. I cannot guarantee we'll ever find El, or Claude again. We may never make it back."

Nonetheless, Dimitri looked at them with a resolute smile.

"But my heart tells me we're not too far off. One day, somehow, I know we'll all be together again. Do your hearts not say the same thing?"

Lysithea and Dedue looked at each other and nodded resolutely, their expressions immediately perking up.

"Let's go, then!"

And so the three set off, knowing their journey, and perhaps that of their lost friends had only just begun.


End file.
